Conventional differential comparators may be used in applications such as microcontrollers. Such comparators generally consist of a differential comparator that can be used to: 1) compare a differential signal against a ground potential, 0V; or 2) compare a single-ended signal against a programmable threshold.
FIG. 1 shows a conventional comparator. The comparator in FIG. 1 is known to and understood by persons of ordinary skill in the art, and details of its structure and operation are known. Briefly, in the differential mode, typically two pins of a device, such as a microcontroller, are routed to the two comparator inputs. Except for possible hysteresis and offset, the comparator effectively compares this incoming differential signal to 0V.
In their single-ended mode, conventional comparators route a single pin to one comparator input, and the output of a programmable voltage generator, e.g., a voltage digital to analog converter (DAC), or VDAC, to the second comparator input. This scheme allows the comparator to compare the voltage on the pin to a programmable threshold. Details of the comparator shown in FIG. 1 are known to persons of ordinary skill in the art, and are therefore not described in any further detail.